Radioactive Pollution: A Never Ending Hazard

Today, in the 21st century, mankind has achieved great feats in every walk of life. New technologies are being developed and upgraded for the efficient working of human civilization.

Newer energy sources are looked for, and their optimal capabilities are harnessed by us.

One such avenue is RADIOACTIVE ENERGY, which has numerous applications in every sector.

Radioactive isotopes (radionuclides) are present naturally everywhere, including our bodies, food, and water.

The half-life of radio-isotopes ranges from hundreds to thousands of years, i.e., the huge amount of time required to reduce their radioactivity by half.

All living beings encounter radiation on a daily basis. It comes from space, naturally occurring radioactive materials (radionuclides) found in the soil, water, and air.

Radiation is basically of two types:

• Non-ionizing radiations: These are electromagnetic waves of longer wavelengths, from near ultraviolet rays to radio waves. They possess energies enough to excite the atoms and molecules of the medium through which they are moving, causing them to vibrate faster. These do not have enough energy to ionize them.
• Ionizing radiations: These are electromagnetic radiations having high energy, such as short wavelength ultraviolet radiations, x-rays, and gamma rays.

The energetic rays like (,  and  etc.) produced in radioactive decay can cause ionization of atoms and molecules of the medium through which they pass and convert them into charged ions.

Alpha (), beta (), and gamma () radiations are produced by the process called radioactive decay.

Their unstable nuclei decay spontaneously and emit radiations. It can affect other non-radioactive atoms to become radioactive and give out radioactive radiation.

If the level of these radioactive radiations increases beyond a certain limit, it causes harmful effects to living beings. This harmful level of radiation emitted by radioactive elements is called radioactive pollution.

GENERATION OF RADIOACTIVE WASTE

Radioactive waste is generated due to the following actions:

• Energy production: Radioactive materials that are produced in nuclear reactors by the fission process itself or by the neutrons emitted are called reactor-produced or by-product material. Radiations may leak from nuclear reactors and other nuclear facilities even when they are operating normally. It is often feared that even with the best design, proper handling, and techniques, some radioactivity is routinely released into the air and water.
• Biological Research: Many of the radio-isotopes commonly used in biological research, such as 3H, 14C, 35S, 32P, 125I, 33P, and 131I, are by-product materials.
• Natural Occurrence: Naturally-occurring radioactive material is any radioactive material that occurs naturally on Earth. All naturally occurring radioactive material is regulated by each state. Radium-226 is widely distributed in rocks, sediments, and soils, along with isotopes of uranium.
• Diagnostics: X-rays are used for general radiology and CT scans. Gamma rays are used for treating cancer. The by-product of these procedures is radioactive.
• Nuclear Tests: Nuclear explosion tests performed out in the atmosphere are a major cause of radioactive pollution and are responsible for increasing the background level of radiation throughout the world.

HAZARDS OF RADIOACTIVE WASTE

Living beings exposed to high doses of radiation display various types of detrimental effects.

Examples of such effects in humans are erythema (reddening of the skin), epilation (loss of hair), cataracts, and “acute radiation syndrome.”

The induction of changes in hereditary traits caused by radiation damage to the chromosomes is known as radiation mutagenesis.

In genetic damage, genes and chromosomes get altered & may become visible as deformations in the offspring (children or grandchildren).

In nongenetic effects, the harm is visible immediately in the form of birth defects, burns, some type of leukemia, miscarriages, tumors, cancer of one or more organs, and fertility problems.

The flora and fauna are also damaged with altered patterns of growth observed in various plants and animal species.

As we all know, the degradation of such radioactive waste is difficult, but there are some biological solutions that would mitigate this problem.

Many microbes like bacteria and fungus could help in the degradation of such radioactive pollutants, thereby helping other organisms to sustain their biological functions.

The red-coloured bacterium Deinococcus radiodurans can resist 1.5 million rads of gamma radiation, about 3,000 times the amount that would kill a human.

The bacterium survives and reproduces in environments that would be lethal for any other organism, and it also resists high doses of ultraviolet radiation.

The most important component of this radiation resistance is the ability of the bacteria to repair damage to its chromosomal DNA.

Researchers hope that they can manipulate it in such a way that it will be able to detoxify the thousands of toxic waste sites that contain radioactive material.

This article is the first part of a two-part series on the topic  “MICROBIAL SOLUTIONS IN BIOREMEDIATION OF RADIOACTIVE WASTE”

REFERENCES:

• http://www.guinnessworldrecords.com/world-records/most-radiation-resistant-lifeform
• https://www.jstor.org/stable/2438741
• Understanding the effects of radiation on Health Editors Dr. Ch. Desaintes, Dr. G. Neale Kelly, Ms Karin Coiffard
• http://www.bic.mni.mcgill.ca/~llchia/HP_lectures/biological_effects.pdf
• http://documents.manchester.ac.uk/display.aspx?DocID=26898
• http://webfiles.ehs.ufl.edu/rssc_biological_effects_ionizing_rad.pdf
• https://www.ehs.washington.edu/rsotrain/radprotectionprinciples/biological_effects.pdf
• http://www.scielosp.org/pdf/rpsp/v20n2-3/12.pdf
• Also Read – Mitigating Antibiotic Resistance With Efficient Wastewater Treatment